Ethan Merritt a écrit :
> On Wednesday 27 February 2008 01:17, Timothée Lecomte wrote:
>> The authors have bypassed gnuplot terminal system almost completely,
>> and only 'splot' seems to be possible.
> To be fair, it is not clear what one should do with a 'plot' command.
> There are only 2 coordinates, not 3, and we don't have 3D equivalents
> for plot elements like boxes and filledcurves. The best approach
> might be to run off a 2D plot as a PNG image, and then map the result
> into 3D using 'splot ... with image'.
Spreadsheet software usually offer a 3D view of any diagram, applying a
depth to every single part of the plot, apart from text maybe. A 'plot'
command on a 3D-"aware" terminal could produce such a thing. I don't
think it's very useful for complex scientific data, but simple
histograms look a little more appealing that way.
>> Daniel Farrell a écrit :
>>> I was listing to the latest FLOSS Weekly Podcast (http://twit.tv/
>>> floss24) in which the topic was POV-Ray; an open source ray tracing
>>> program. After some idle surfing I found that somebody has contributed
>>> patches to gnuplot for a POV-Ray terminal; fancy ray-traced figures
>>> found here, (http://t-kita.net/gnuplot_povrml/) and the submitted
>>> patch here, (http://sourceforge.net/tracker/index.php?func=detail&aid=1262281&group_id=2055&atid=302055
>>> I cannot apply this patch successfully to the gnuplot-4.0.0 source? I
>>> am going like this,
>>> cp -r gnuplot-4.0.0 gnuplot
>>> cp -r gnuplot gnuplot-patch
>>> mv povray.diff gnuplot
>>> cd gnuplot
>>> patch -p1 < povray.diff
>>> Anybody have gnuplot and POV-Ray working together?
>> Hi Daniel,
>> You have found a wonderful peace of work there ! The povray figures that
>> are given in http://t-kita.net/gnuplot_povrml/ are simply gorgeous. The
>> two authors, KITA Toshihiro and MIYATA Shigeo, have done something that
>> others (I included) have probably dreamed of sometimes : let the
>> terminal driver handle 3D instead of letting gnuplot core do all the
>> work. Here POV-ray gives a very valuable addition compared to gnuplot 3D
>> routines : it does true (isometric) perspective, plus realistic shading,
>> something that is desperately lacking in gnuplot today. There is a patch
>> on SF.net for adding perspective to gnuplot 3D routines, but the author
>> did not work on it until inclusion in CVS, and as far as shading (or,
>> plot points as little spheres, etc), I had never seen such a thing for
>> There's at least one thing that this work has not achieved according to
>> the figures : it's pm3d coloring, which is very important for 3d data
>> visualization. Perspective + shading + pm3d coloring of surfaces plots
>> would be a great achievement. Let me add that POV-ray, like openGL, is
>> probably able to draw polygons colored with gradients, something that is
>> very difficult or impossible with most 2D drawing API (Cairo, for
>> example, cannot do it). Gradients coloring makes surface plots much
>> nicer, and gnuplot already has the mechanisms to do that, but they are
>> used by a single terminal driver, namely the SVGA one, the one that
>> Ethan never achieved to see working, the one that is also presumably
>> unsecure. Too bad, isn't it ?
>> Let's talk about the code now.
>> You mention the following patch :
>> . This is not the patch that gave the POV-ray figures. This patch on
>> SF.net only does 2D rendering, as the author, Gaël Varoquaux, explains
>> on the page:
>>> This patch is not terribly iseful as long as the 2D/3D code
>>> in gnuplot is not refactored. This patch only implements the
>>> 2D drawing API (as there is no 3D API currently).
>> However, the right patch is provided in
>> First, it is offered as a public domain work, so there is no license
>> issue. Good.
>> It's not really large:
>>> # diffstat gnuplot_povrml-0.3.patch
>>> src/plot2d.c | 21 ++
>>> src/plot3d.c | 19 +
>>> src/povray.c | 538
>>> src/term.h | 6
>>> src/vrml.c | 399 +++++++++++++++++++++++++++++++++++++++++
>>> term/povray.trm | 152 +++++++++++++++
>>> term/vrml.trm | 151 +++++++++++++++
>>> 7 files changed, 1286 insertions(+)
>> However, after a quick glance at the patch, it's not in a state that
>> would allow it to be included immediately. The authors have bypassed
>> gnuplot terminal system almost completely, and only 'splot' seems to be
>> Steps to make that patch better :
>> - make it work with gnuplot CVS,
>> - identify key functions to design an API to extend the current terminal
>> one in gnuplot.
>> - get full 2D + 3D (maybe mix this patch with Gaël's one)
>> Thanks Daniel for making this work known !
>> Best regards,
>> Timothée Lecomte